Automatic testing and resetting means for electrothermal protectors.



No. 869,554. I PATENTED OCT. 29. 1907.

F. B. 000K. AUTOMATIC TESTING AND RESETTING MEANS FOR BLBGTROTHERMAL IPROTECTORS. urmouxon nun nu 19,1906.

UNITED STATES PATENT omen- FRANK B. oooK, or ornoioo, rttmors.

AUTOMATIC TESTING BEBET'I'HIG ANS FOB ELEO'I'BOTEERIAL PBOTEGIOBS.

Application ma lay in;

To all whom it may concern: Y

Be it known that I, Faanx B. Coox,.a citizen of the United States ofAmerica, residing at Chicago, in the county of Cook and State ofIllinois, have invented a new and useful Automatic Testing and ResettingMeans for Electrothermal Protectors, of which the following is aspecification, reference being bad to the accompanying drawings,illustrating same.

My invention relates to electro-thermal apparatus, and is illustrated inconnection with protective apparatus for telephone systems.

The principal objects of my invention are to provide a test plug forsuch apparatus adapted to automatically test and reset the thermalprotectors, to reset the protective apparatus to operative position, andto be used as a test plug for testing the several circuits of thesystem; and to provide simplicity of construction in such a testing andresetting device.

Other objects will be apparent from the following specification.

In apparatus of the class herein described it is generally customary toset same to operative position by some manual msans, without testing thethermal-pro, tectors. If the thermal protectors are tested, this isgenerally done separately from resetting the apparatus. In my presentinvention 1 provide a device which automatically closes a heatingcurrent hrough the thermal protectors, heats same and operates same as atest there on, and at the same time automatically resets the operatedapparatus to operative position. This testing and resetting device maybe also used for testing the several circuits through the protectiveapparatus without testing the thermal protectors. l

The broad idea of closing a current of electricity through a thermalprotector to reheat same and reset same inthe circuit for anotheroperation is contained in my copending application for Letters Patent,Serial No., 271,662, filed July 28th, 1905. A modification of theinvention contained in said application Serial No., 271,662, is showndescribed and claimed in my copending application Serial No, 304,929,filed March 8th, 1906.

Referring to the accompanying drawings, Figure 1 is a side elevation ofa pair of telephone protective apparatus with the testing and resettingplug inserted therein; Fig. 2 is an edge elevation of Fig. 1; Fig. 3 isa side elevation of a pair of the protective apparatus withopt thetesting and resetting plug; the apparatus on the left-hand side beingshown in set position and that on the right-hand side being shown inoperated position; Fig. 4 is a side elevation of the testing andresetting plug only; Fig. 5 is an edge elevation of Fig.

r 1.5m Patent.

Patent ed Oct. 29, 1907.

. Spring members 1 1, 2 2, 3 3, and 4 4, are mounted on the ground plate5 which is preferably formed as shown, and are insulated from each otherby suitable insulating washers 6 6. Between the ends of springs 2 2 andthe ground plate oars inserted lightning arr-esters 7 7.

Each thermal protector 9 is provided with a toothed shell 23 inclosingheat-producing means through which a pin is soldered by easily-fusiblematerial. The pin is held stationary bythe ears '8 8 and the remainderof the thermal protector is free to turn on the pin when theeasily-fusible material is softened. Each spring 1 is provided with aportion 10 adapted to engage a tooth-of a thermal protector 9 when theapparatus is in operative position. When an abnormally large currenttraverses a thermal protector for a sufficient length of time, theeasily-fusible materialtherein becomes softened and allows the portion10 of spring member Ito rotate the thermal protector 9 and-releaseitself therefrom as shown on the right of.Fig. 3, thus opening thecircuit through the protector 9 and allowing the easily-fusible materialagain secures theoperable portion thereof to the-pin, as originally.When the thermal protector operates, as just described, spring member 1causes the insulating pin 11 to deprem spring members 3 and 4 intocontact with ground plate 5 and thereby ground the line spring 2' andclose an alarm circuit as will be readily understood. Spring membars 2 2are preferably the line springs and lead to the line conductors, andspring members 1 1 are preferably 1 the switchboard springs and lead tothe switchboard conductors. Springs 3 3 are the grounding springs forline springs 2 2, and springs 4 4 are the alarm circuit springs and arepreferably connected in common. On each side of ground plate 5, springmembers 3 and 4 lie in same plane. I

The testing and resetting plug of Fig. 4 is provided with spring members12 12, 13 13, 14 14, suitably mounted on a handle portion 24 andinsulated from each other by strips of insulation 15 15. Spring members12 12 areadapted to engage line springs 2 2, spring members 13 13 areadapted to engage portions 16 16 of switchboard springs 1 l and therebyhold the latter out of engagement with the thermal protectorsrespectively, when the plug is into the protective apparatus as shown inFig. 1 Each battery 17 is conne in circuit with spring members 12 and 14on one side of the plug, and is for the purpose of supplying current toa thermal protector 9 to heat me for operation when it is desired .totest the protoctor.

i Intestingathermalpi'otectoramlresettingthepro- Spring members 2 2 areprovided with ears 8 8 thereoni adapted to hold the thermal protectors 99 therebetween. 1

the latter to cool. When the thermal protector 9 cools,

9 9, and spring members 14 14 are adapted to engagethe toothed shells 2323..of thermalprotectors 9 9,

tective apparatus to operative position, the testing and resetting plugis inserted into the apparatus as shown in Fig. 1, which closes thecircuit of each battery 17 through spring members 12 and 14 and athermal protector 9. The current from battery 17 soon heats theprotector 9 and softens the easily-fusible material therein, whereuponspring member 14 turns the protector 9 and releases itself therefrom andtakes 1 the position 18 shown in Fig. 1. The current of battery 17 -isnow broken from the protector 9 and the latter cools. The testing plugmay now be withdrawn from the protective apparatus, such withdrawalsetting the portions 10 10 of spring members 1 1 into engagement withthe toothed shells 23 23 of the thermal protectors 9 9 and therebysetting the protective apparatus for operations Either one or both ofthe protectors 9 9 may be tested with one insertion of the plug. Whenthe testing plug is inserted into the protective apparatus, both springmembers 14 14 are manually pressed into engagement with the thermalprotectors 9 9 if it is desired to test both of the latter. If it isdesired to test only one protector 9, then one spring member 14 only isdepressed. If is is not desired to test either of the protectors 9 9,then neitherof the spring, members 14 '14 is depressed.

The testing plug may be used simply as a means for testing the line andswitchboard circuits, conductors 19 19 being connected with line springs2 2 for testing the line circuit, and conductors 20 20 being connectedwith switchboard springs 1 1 for testing the switch, board circuit.Conductors 19 19, 20 20, may be connected to any suitable switch andtesting instrument.

When the thermal protectors 9 9 .are heated and operated by a currentthrough the testing plug, as-described above, such operation shows thatthe protectors 9 9 are in condition to be operated again when theapparatus is reset. If the protectors 9 9 do not properly heat andoperate by current supplied through the testing plug, it shows that theyare not in condition to be operated. when the apparatus is reset, andshould therefore be replaced by new protectors.

. The testing plug may be inserted into the protective apparatus whethersame is in a setor operated position. If the apparatus is in operatedposition, the free ends of springs 13 13 will pick up the "portions 16$6 of switchboard springs l 1 and reset the portions 10 10 intoengagement with the protectors 9 9 when the plug is removed from theapparatus. Each spring 13 on the testing plug is preferably providedwith a hole 21 therein adapted to accommodate the point 22 of portion 16of spring member 1, so as to allow spring 13 to substantially engage theportion 16. The point 22 projects somewhat into the hole 21..

I do not wish to limit this invention to the exact on the cartridge.

details of construction, nor to the particular thermal protectors 9 9,herein shown and described. What I claim as my invention and desire toby Letters Patent, is: I

1. A testing andrcsetting device for an electrotherinal device of thecharacter described, comprising means for applying current to theelectrothermai device to heat secure same andfor operating same whenthus heated, the said resetting device being constructed to reset theelectrotherniai device in circuit for operation when removed therefrom.g

2. A testing device for a heabcal'tridg'c operable in a.

given direction, comprising means for applying current to the cartridgeto heat same, and for operatingthe cartridge still farther in the samedirection when thus heated, as a" tridge to heat same, and for turningthe cartridge still farther in the same direction whenthus' heated, as atest 4. A testing device for telephone protective apparatus hayingthermal protectors, comprising means for making:

electrical connections with the apparatus for testing the line andswitchboard circuits separately and means for applying current to athermal protector and for operating same when heated, as a test on theprotector.

5. A device to be applied to electrical protective apparatus, comprisingmeans for making electrical connections for testing the several circuitsthrough the apparatus separately, and means for heating and operating aprotector of the apparatus, the said device being constructed to resetthe apparatus for operation when re moved therefrom.

6. A testing device for electrical protective apparatus having a thermalprotector, comprising means for making electricamconuections with theapparatus for testing the several circuits therethrough separately andmeans for.

, cartridge having a .series of engaging devices and means means foroperating the heat-cartridge when same is heated'and thereby bringingthe said engaging devices successively into engaging position for theirengaging means; and means for resetting the said engaging means intoengagement withan engaging device for another operation. I p I 8. Atesting device for an e'flectro-thermal protector, the-latter havingmeans engaged therewith vto operate same under abnormal currentconditions, comprising means for bearing the said engaging means out ofengagement with the protector, means for applying current to theprotector to heat same, and nieans for operating the protector as atestihercon when same is suitably heated.

As inventor of the foregoing-,1 hereunto subscribe my name in thepresence of two subscribing witnesses, this 16th day-of ltiuy, 1906. g

' ream; s. COOK. Witnesses:

FREDERICK R. IAiuum, C. C. NswBunN.

